<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=
    , initial-scale=1.0">
    <title>视距</title>
    <style>
        .fa {
            perspective: 1000px;
        }

        .son {
            width: 200px;
            height: 200px;
            background: palegreen;
            margin: 100px auto 0;
            transition: all 2s;
        }
        .son:hover {
            transform: translateZ(300px);
            border-radius: 50%;
        }
    </style>
</head>
<body>
    <div class="fa">
        <div class="son"></div>
    </div>
</body>
</html>